Calculating place-based transit accessibility: Methods, tools and algorithmic dependence

Abstract

To capture the complex relationships between transportation and land use, researchers and practitioners are increasingly using place-based measures of transportation accessibility to support a broad range of planning goals. This research reviews the state-of-the-art in applied transportation accessibility measurement and performs a comparative evaluation of software tools for calculating accessibility by walking and public transit including ArcGIS Pro, Emme, R5R, and OpenTripPlanner using R and Python, among others. Using a case study of Toronto, we specify both origin-based and regional-scale analysis scenarios and find significant differences in computation time and calculated accessibilities. While the calculated travel time matrices are highly correlated across tools, each tool produces different results for the same origin-destination pair. Comparisons of the estimated accessibilities also reveal evidence of spatial clustering in the ways paths are calculated by some tools relative to others at different locations around the city. With the growing emphasis on accessibility-based planning, analysts should approach the calculation of accessibility with care and recognize the potential for algorithmic dependence in their calculated accessibility results.

Dynamic geographical accessibility assessments to improve health equity: protocol for a test case in Cali, Colombia

“…Accessibility studies assess distance or the shortest average travel time to the nearest facility; they seldom assess equity and are typically geared towards field experts. [12][13][14] These studies usually explore broad service categories without focusing on specific services people might need. They are lengthy, costly, and rarely address the dynamic temporospatial nature of accessibility, such as its links to traffic congestion.…”

“…This new line of research explores if market forces and land use plans achieve service accessibility and if this holds for populations in situations of vulnerability. 9, 12,29 The need for this study This proposal spurs the scaling up and replicating of accessibility analyses to health services in urban centers while promoting accessibility indicators based on dynamic travel times. The research demystifies the use of big data and analytics that reveal the needs of citizens, including the most vulnerable.…”

Public transit cuts during COVID-19 compound social vulnerability in 22 US cities

“…Transit accessibility often considers four key factors: (1) destination attractiveness considering the spatial distribution of opportunity locations and service quality, (2) transit service characteristics (e.g., availability of transit stations, routes, reliability, and cost of using transit service), (3) temporal constraints (e.g., conflicts in transit schedule, operations hours of opportunity locations, and travel time budget of transit users), and (4) socio-economic characteristics of transit users ( Malekzadeh and Chung, 2020 ). Mapping isochrones is a popular network-based space-time approach to quantifying transit accessibility ( Higgins et al, 2022 , Lei and Church, 2010 , O’Sullivan et al, 2000 ). An isochrone is an area reachable from a specific location given a travel time threshold or other cost parameters and mode-specific criteria ( Lei and Church, 2010 , Levinson and Wu, 2020 , O’Sullivan et al, 2000 ).…”

Dynamic Geographical Accessibility Assessments to Improve Health Equity: Protocol for a Test Case in Cali, Colombia (Evaluaciones Dinámicas De Accesibilidad Geográfica Para Mejorar La Equidad: Prueba En Cali, Colombia: Protocolo De Investigación)

“…Accessibility studies assess distance or the shortest average travel time to the nearest facility; they seldom assess equity and are typically geared towards field experts. [23][24][25] These studies usually explore broad service categories without focusing on specific services people might need. They are lengthy, costly, and rarely address the dynamic temporospatial nature of accessibility, such as its links to traffic congestion.…”

“…This new line of research explores if market forces and land use plans achieve service accessibility and if this holds for populations in situations of vulnerability. 1,23,39 The Need for This Study…”